The primary aim of this study was to investigate the effects of extreme weight cutting on competitive sports performance of combat sports athletes who participated in the 20th Nation Sports Festival, Edo 2020. A total of 150 male and female combat sports athletes who took part in the festival were used. The athletes’ weights were taken on arrival to camp. These were subtracted from their festival weight classes. The difference is the weight cut. The athletes were classified into: Those that did not cut weight, Actual Weight (AW), those involved in Moderate Weight Cut (MWC) and Those indulged in Extreme Weight Cut (EWC). The competitive sports performances/scores of the combat sports athletes and their weight types were recorded during the sports fiesta. The mean plots of the scores by weight types indicated that combat sports athletes who indulged in extreme weight cut has the least mean scores during the sports competition. Indicating that extreme weight cutting lead to poor competitive sports performance among the combat sports athletes who participated in the sports festival.